Add method to modify game time properly

[tsjost]

...and make the time-cheaty debug keys not under/overflow the clock.

[MrSapps]

magic?

[tsjost]

maths + magic

[tsjost]

The unit tests require GameWorld and GameState, which are currently only available when RW_TEST_WITH_DATA is set (which it's not on the CI servers), so I've had to move the tests inside the #if -- even though they don't require any data.

[danhedron]

This is good. Only 1 issue I can see: pressing [ doesn't roll the clock back an hour, it only alters the minutes. It looks like the test cases are correct and pick up this issue too.

[tsjost]

@danhedron I don't understand what you mean. [ will move the clock back 30 minutes. If the clock is less than xx:30, the hour will be decremented. This is shown to work in the tests.

[danhedron]

I get this output from the tests:

/home/dan/dev/openrw/tests/test_GameWorld.cpp(37): error in "test_offsetgametime": check 0 == gw.getHour() failed [0 != 1]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(41): error in "test_offsetgametime": check 23 == gw.getHour() failed [23 != 1]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(45): error in "test_offsetgametime": check 0 == gw.getHour() failed [0 != 2]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(49): error in "test_offsetgametime": check 0 == gw.getHour() failed [0 != 2]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(53): error in "test_offsetgametime": check 8 == gw.getHour() failed [8 != 10]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(57): error in "test_offsetgametime": check 7 == gw.getHour() failed [7 != 10]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(61): error in "test_offsetgametime": check 7 == gw.getHour() failed [7 != 11]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(65): error in "test_offsetgametime": check 7 == gw.getHour() failed [7 != 11]
/home/dan/dev/openrw/tests/test_GameWorld.cpp(69): error in "test_offsetgametime": check 9 == gw.getHour() failed [9 != 13]

$ gcc --version                                                                                                                               Wed 10 Aug 22:12:48 BST 2016
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.1) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE

[tsjost]

@danhedron I force-pushed, please see if it works now? The previous code shouldn't have worked anywhere so I'm not sure why my tests passed.

[danhedron]

Works for me. Tests are passing locally. +1

[JayFoxRox]

Note that this is the only test case which goes forward by non-30 minute increments.
As we have 2 directions (+ and -) this is not enough to test all cases (do we know that -25 works?).

We should have more cases which give a remainder if 60 is divided by the minutes and we should have that in both directions (+ and -). I didn't think about this very much tho, so maybe it's useless.

[JayFoxRox]

Only found nits (see diff comments above).

Tested this locally - works fine. I'd like to have an option to reset or control the seconds too, but it'd be beyond the scope of this PR and I'm not sure how one could implement it easily either.

LGTM.